An image duplicating apparatus having an automatic document feed module in addition to a main duplicator module is well known and is in wide use. An automatic document feed module is the apparatus which is operative to automatically feed an original document or successively a plurality of original documents to a predetermined position on the document support table of the duplicator module and withdraw the document or each of the documents from the document support table upon completion of the cycle of copying operation for the document.
An automatic document feed module of the type having a "multiple-job" feature is also known which allows selection of the quantity of printed outputs to be produced for each of a plurality of original documents. Thus, an operator of the duplicating machine having such a type of automatic document feed module may set the module in a manner to produce, for example, three printed outputs for each of a first set of original documents, a single printed output for each of a second set of original documents, and five printed outputs for each of a third set of original documents. With the automatic document feed module set in this fashion, the duplicating apparatus produces printed outputs in quantities respectively preset for individual groups of documents and will thus allow the operator to save the time and labor that would be otherwise necessitated for the production of printed outputs of such diverse quantities.
In the meantime, an image duplicating apparatus is further known which is equipped with a machine locking and output counting device adapted to maintain the apparatus in a locked condition unless a "key/counter", special plug-in unlocking and output count register means, is loaded into the device. When actuated by the key/counter, the locking and output counting device, hereinafter referred to as machine management system, unlocks the duplicating apparatus and is operative to count the quantity of the printed outputs produced after the key counter is loaded into the management system.
In the key/counter for use with such a machine management system are given authorizations for users authorized to use the apparatus so that the authorized users alone are permitted to unlock and use the apparatus. When a cycle of copying operation which may consist of a single printing step or a succession of printing steps is complete, the number of the printing steps repeated and counted by the management system after the key/counter was loaded into the system is registered into the key/counter and is displayed thereon. The number of the printing steps repeated during the cycle of copying operation just terminated is added to the number of the printing steps which had been registered in the key/counter so that the particular bearer of the key/counter is enabled to know the total quantity of the printed outputs which have been produced since the count registered in the key/counter was last reset.
A automatic document feed module having the multiple-job feature as above described is advantageous in that printed outputs can be produced in different quantities for a plurality of groups of original documents. Whether the groups of original documents currently set on the automatic document feed module belong to different users or to one and the same user is however not taken into account in such a multiple-job automatic document feed module. On the other hand, a machine management system of the described nature is useful for enabling each of the authorized users of a single duplicating apparatus to use the apparatus at his own expense for the printed outputs produced through the use of the key/counter which the particular user possesses. Thus, the printed outputs produced through the use of a key/counter in the possession of one authorized user are distinguished from those produced through the use of a key/counter possessed by another authorized user. In other words, an automatic document feed module equipped with a machine management system be capable of distinguishing a group or groups of original documents belonging to one authorized user from a group or groups of original documents belonging to another authorized user of the apparatus.
Where a machine management system is incorporated into an automatic document feed module having multiple-job capabilities, a user desiring to produce duplicates of originals broken down to a plurality of groups, the user will be required to load the key/counter into the management system for one of the groups and thereafter into the management system for another group of original documents. If the user fails to exchange the key/counter from one management system to another and if it happens that a count of printed outputs is stored in the latter, the count in the particular management system in addition to the count stored in the former will be registered into the key/counter. The result is that the user is compelled to be responsible for not only the outputs produced for him or her but also the outputs produced for another user.